1. Field of the Invention
This invention relates to a recording unit which records images by jetting a liquid imaging material, and more particularly to a recording unit which draws images by electrostatic generation of intermittent jetting of a liquid imaging material in response to a signal.
2. Description of the Prior Art
Facsimile is employed as one method for obtaining a picture in the form of an assembly of fine, linear or continuous, dotted line picture elements which are intermittent in accordance with a signal. As a recording method therefor, use has heretofore been made of, for example, the so-called spark printing process in which a surface layer previously formed on a recording member or medium such as paper, synthetic resin film or the like is ruptured as by discharge to expose a coloring material contained in the layer to thereby record images, or of the so-called electrostatic recording process in which an electrostatic latent image is formed as by corona discharge on the surface of a recording member previously insulated and then developed with a dry or liquid toner, electrophotographic recording process in which a latent image produced by irradiating the surface of a photosensitive recording member by a light beam is developed, or thermal development process.
These conventional methods are disadvantageous in the necessity of some previous treatment of the recording member and in involving a troublesome developing process. Further, one method that has been used for directly recording picture elements in an imaging material is to intermittently bring a recording unit such as a ball pen, a glass pen or the like into contact with a recording member. With this method, however, since the intermittent recording operation is achieved mechanically, it is low in response speed and noisy and, further, since recording is made by direct contact of the recording unit with the recording member, this method is not suitable for use with recording members whose surfaces are uneven and not smooth.
Further, with conventional recording units of the type employing jetting of a liquid imaging material, images being drawn are made intermittent by deflecting a previously generated jet by the pressure applied to the imaging material using an acceleration electrode and a deflection electrode, so that it is necessary to provide a removing device for receiving the imaging material during suspension of recording. Therefore, in the case of recording with one process by closely arranging many recording units, apparatus becomes inevitably complicated and bulky in its entirety.